Anisotropic electrically conductive films are widely used when mounting electronic components such as IC chips on substrates. In recent years, demand has risen for increasingly high wiring density in small electronic devices such as mobile phones and notebook-size personal computers. One well-known technology for achieving this high wiring density involves utilizing an anisotropic electrically conductive film in which electrically conductive particles are uniformly disposed in a lattice form in an electrically insulating adhesive layer of the anisotropic electrically conductive film.
However, there is a problem in that variations in connection resistance occur even though the electrically conductive particles are evenly disposed. This is because, when the electrically insulating adhesive is melted, electrically conductive particles located above the edges of the terminals may flow to spaces between terminals and thus are less likely to be held between upper and lower terminals. One proposed technique for solving this problem involves setting a first arrangement direction of the electrically conductive particles as the longitudinal direction of the anisotropic electrically conductive film and setting a second arrangement direction that intersects with the first arrangement direction to be inclined at an angle of from 5° to 15° relative to a direction orthogonal to the longitudinal direction of the anisotropic electrically conductive film (Patent Document 1).